The principle of the switching power supply optocoupler short-circuit method
The principle of the switch power supply optocoupler short-circuit method is to control and protect the power switch through a optocoupler. When the switching power supply malfunctions or exceeds the set working conditions, the optocoupler will short-circuit the feedback signal to the control circuit to stop the output power supply and prevent damage.
Switching power supply is a common type of power supply in modern electronic devices, which has the characteristics of high efficiency, stability, and reliability, and is suitable for various application fields. Switching power supplies are generally composed of input filtering circuits, rectification circuits, energy storage capacitors, power switching devices, output adjustment circuits, and control and protection circuits. The control and protection circuit is an important component of implementing the operation control and fault protection of the switching power supply.
Optocoupler is a device that can convert electrical and optical signals into each other. It consists of photosensitive elements (such as photodiodes) and light emitting elements (such as light-emitting diodes), and is isolated from each other by a light coupling medium. In a photoelectric coupler, when a voltage is applied to the input terminal, the light emitting element emits a light signal, which is transmitted to the photosensitive element through the action of the optical coupling medium, and then generates an electrical signal output.
Switching power supply optocoupler short circuit method is a commonly used fault protection method, which uses optocouplers to connect the output current of the switching power supply with the feedback circuit, forming a closed-loop control system. When the switching power supply is working normally, the output current is transmitted to the feedback circuit through the optocoupler without short circuiting. But when the switching power supply malfunctions (such as overcurrent, overvoltage, overheating, etc.) or exceeds the set working conditions, the output current will suddenly change, and the optical signal passing through the optocoupler will also suddenly change, feedback to the control circuit.
The control circuit will determine the status of the switch power supply by detecting changes in the optical signal of the optocoupler and take corresponding protective measures. For example, when the output current is too high, the optocoupler will short-circuit the feedback signal to the control circuit, and the control circuit will automatically cut off the input power of the switching power supply, stop the output voltage, and avoid damaging the equipment; Alternatively, the control circuit can change the output power of the switching power supply through the received optical signal to achieve the purpose of protection.
The switch power supply optocoupler short-circuit method has the following advantages: firstly, due to the use of optocouplers for signal transmission, it can effectively isolate the switch power supply and control circuit, improving the safety and reliability of the system; Secondly, the detection speed of short-circuit feedback signals is fast, which can quickly respond and cut off the switch power supply, avoid the expansion of faults, and protect other electronic devices from damage; Once again, the optocoupler short-circuit method for switching power supplies has the characteristics of simplicity, low cost, and ease of implementation, making it suitable for various types and scales of switching power supplies.
In summary, the switch power supply optocoupler short-circuit method utilizes optocouplers to control and protect power switches. Through the detection and feedback of optical signals, the switch power supply can be quickly cut off, avoiding the expansion of faults and equipment damage. It is an efficient and reliable method for controlling and protecting switching power supplies, widely used in electronic devices across various industries.
